Rotary engine



July l, 1941.

E. E. BQWERS Erm.

ROTARY ENGINE Filed June 25, 1940 5 Sheets-sheet 1 T TURA/Ys July l, 1941.

E. E. BOWERS ET AL.

Filed June 26. 1940 ROTARY ENGINE 5 Sheets-Sheet 2 July l, 4941.. E. E. BOWERS r-:TAL 2,247,474

ROTARY ENGINE Filed June 26, 1940 5 Sheets-Sheet 5 July 1, 1941. E. E. BOWERS Erm.

ROTARY ENGINE Filed June 26, 1940 5 Sheets-Sheet 4 E. E. BOWERS ETAL ROTARY ENGINE `Iuly l, 1941.

Filed June 26, 1940 5 Sheets-Sheet 5 I N v5 N Top5 Ew. E. Bor/:ps CHAP/.cs M TUA/f);

Z l l T 7'0 PNE rs Patented July l, 1941 ROTARY ENGINE Earl E. Bowers, Lebanon, and Charles IVI. Turney, Indianapolis, Ind.

Application June 26, 1940, Serial No. 342,456

i Claims.

This invention relates to a rotary engine of the positive displacement type and has for a primary object the formation of a structure that will have a high thermal efciency, be exceedingly compact, and have an exceedingly low mechanical friction loss throughout the various moving parts.

An important feature of the invention is the provision of a tortuous, antennate steam travel whereinthe applied pressure in tending to leak past rotary members meets a residual or counterflowing pressure, all without frictional packing or glands.

A still further important object of the invention is to provide a sealed unit having but a single moving member (drive shaft) extending therefrom.

These and many other features and advantages of the invention will become apparent to those versed in the art in the following description of one particular form of the invention as illustrated in the accompanying drawings, in which Fig. l is a top plan view of a structure embodying the invention in partial section;

Fig. 2, a central, vertical, longitudinal section;

Fig. 3, a transverse vertical section on the line 3--3 in Fig. 2 with the rotors about to receive steam pressure;

Fig. e, a like section on the line l--fl in Fig. 2 with steam pressure cut orT after an initial travel of the rotors; and

Fig. 5, a section similar to Fig. 3 but with the rotors revolved substantially 320 degrees from the positions shown in Fig. 3.

Like characters of reference indicate like parts throughout the several views in the drawings.

A short externally cylindrical body I is formed to have a pair of concentric upper cylinders II and i2 and a pair of lower like, concentric cylinders I3 and lil. In order to maintain the cylinders II and I2 vertically above the lower cylinders i3 and lil, the body IIJ is provided with a pair of feet I5 and It. The body I0 is provided with a central partitionwall Il serving as the inner ends respectively of the cylinders II, I2 and I3, Ill. This partition I1, Fig. 2, is provided with upper and lower `circular openings therethrough concentric with the axes of the cylinders Il, I2 and I3, Ill respectively. The upper and lower pairs of cylinders intersect chordally Whereby the corresponding upper and lower cylinder in each pair is normally in open communication one with the other.

A rotor I3, Fig. 3, is formed in the general shape of a hollow cylinder to have gear teeth I9 out transversely across its periphery around a opening through the partition Il.

major portion thereof. A vane or major tooth 20 extends radially from the circumference of the rotor and immediately behind that vane a depressed area 2i is provided, the vane 2 and the area 2| being between the ends of the rotor periphery carrying the teeth I9.

From one side of the rotor I8 extends a trunnion 22 to serve as a bearing support. From the other side of the rotor I8 extends a boss 23 having an external diameter less than that of the This rotor I8 is placed in the cylinder Il to have this boss 23 extend into the opening through the partition Il and a like rotor Zbl is placed in the adjacent cylinder I2 to have a boss 25 entered into that same partition opening to abut the boss 23 and these two rotors I3 and 2G are secured one to the other by any suitable means, such as the pins 26 and bolts 2l. rI'he rotor 24 is substantially a duplicate of the rotor i3, particularly in reference to its peripheral formation, Fig. li. The rotor 24 has its vane 28 turned and xed substantially 180 degrees around from the vane 2li of the rotor I8.`

The rotor 2li carries a trunnion 23 extending from its outer face.

In like manner, rotors Si) and 3| are placed in the cylinders I3 and Iii and these rotors secured one to the other through the opening provided in the partition il. The rotor I8 is positioned circumferentially in its cylinder in reference to the position of the rotor 3|] in the cylinder I3 below to have the minor teeth lil of each mesh with each other in close driving relation, and to have the recessed area 2l located to receive the vane 32 of the rotor 3i] therein in the nature of a gear i tooth in driving relation with the vane 20 so that carries respectively trunnions 34 and 35.

A cylinder cover plate 36 is brought against the side of the body IB to form the outer sides of the cylinders l2 and Ill. The plate 36 is secured to the body It by any suitable means with a steam tight connection, such means being herein shown as bolts 3l. The respective trunnions 29 and 35 of the rotors 2li and 3| extend through bores provided in the plate 35 to be carried by the inner races of the respective ball bearings 38 and 39,

these bearings being mounted in counterbores entering from the outer side of the plate 36 and having the securing plates and 4I.

Likewise on the other side of the body lll is a cover plate 42 brought against the body lil and there secured by any suitable means, such as by the bolts 43y in steam tight connection therewith. This plate 42 forms the outer side wall of the cylinders lifand I3.

to be carried by the inner races of the ball bearings 43 and 44 mounted in counterbores in theA plate 42 and there secured by the plates- 45- and 46.

Thus the two upper rotors I2 and as these rotors may turn, the lower rotors 36 and 3| will be turned likewise on their sup-` porting bearings 39, and. 44.

The minor. toothed periphery of. each ofthese four rotorshasa diameter. less than that of. the cylinders, whose diameters4 in. the present form are identical. Thisl difference in diameters leaves an annular chambery between the walls of each cylinder and its rotor therein. The vane on each rotor hasa. substantial circumferential length and isin, close running fit with thewall of its cylinder.` It doesnot, however, come into actual Contact therewith. The widthsof. each of the four respective rotorsare .made to be such that they are free from contact with the partition I1 and the enclosing plates 35 and 42.

A.. drive shaftlll. extends axially with a relatively free sliding kt` through the trunnion34,

the rotorsandl, and enterswith a suitable driving connectioninto a bore provided in the trunnion 3,5 of the rotor 3 i In the present form, this.l connection of the shaft 41` withthe trunnionuisfhy. a spiine-t and the shaft is` free to travelulongitudinally in respect. to this connerctionarid itspassage through therotors and the truh,rlOUtz 34... It is to; be appreciated that this shaft 41 could equally as well be connected with the trunnionfZS of the rotor Eiland extend through the roter L8. 'Ihe V location of. the shaft isl a matterV of; choice, between these two,` connections. A `housing v cover. 43; is I connected with a4 s,teamtight jointagainst the, plate 42 by'v the.

bolts, 4.3. This; cover` 48 carries a. suitable -load bearing# 4S for the-shaft, 4.1, the bearinginthe presenti instance beingy indicated asa double thrust.f ball` beari11,g the inner races of which are located ontheshaftiflbetween the inner shaft.v collar 5.4i and; an outer` retainingnring,V 5|.' In`4 theforrnV4 herein. shown, this bearing 49 is. retainedL in position by means of the bearing Cap..5.2. pullcdtaeant the @over 4S. 'An Outer felt packing 53 3encircles the shaft 41 solely asa 'meansbffpreven ggoil from escaping from the bearing;tftv 1h15.thick/ille.' ydoes not toanv extentlserve as astearn packing,

.Fitting into. a Counterbore from the inner face of the-.cover 441s a packing unit 54 which is commercially lob,ta-finaltile. for-.the p urpose about to be describedandjits. detailsper. se. do` notlenter into the invention. This packing unit 54 `is of thesQring pressedbellows type forming a high pressure steamsealthrough the, plate 55 urged against, the` face/,ofthe collar 5.6, Fig. 2. This packing unit v 54- serves to. prevent. steam leaking` longitudinally of Ithe shaft- 41Y outwardly toward the` bearing. 49. The shaft 41 is the onlyk eXten- 'I-he rotor trunnions 22 and. 34 extendfthrough boresl provided in the plate 42` I8 and: 24; areV mounted as a unit to turn on the bearings 4d and 43 within their respective cylinders Il. andr v0n the other end of the engine is a housing cover 55 which is carried against the plate 36 with a steam tight connection by means of the bolts 31. Therefore, even if steam may leak from the cylinders Il, l2 and I3, I4 past the faces of the rotors therein and out through or around their respective trunnions into the charnbers formed between the plates 36 and 42 and their respective covers 56 and 4B, that steam can not escape from the engine,4 but a pressure may build up in those chambers'and this pressure is utiized as will hereinafter appear.

Fixed to the shaft 4l is a timing gear 51. This gear 51; is in constant mesh with the valve gears 5S and 59, Fig. l. The gear 58 is fixed on the Y outer end of the intake valve 6E, Fig. l, this valve-consisting essentially of a hollow cylindrical member.i rotatably mounted in a chamber extending through the body I6 with its axis in the-plane-of intersection of the upper and lower cylinders. The valve. 6 0 is. carried. by the ball bearings. 6.1` andZ near itsrespective, ends, these.. bearings. being mounted and.. secured' inthe respective cylinder. en d plates 3 6' and 4 2. The valve f5.6. isprovided with. a port. 63.' to register with an opening. 641nto the cylinders III. and i3, and a-second port,.6.5f to register. with an opening 56. into thechambersv I Z and. i4.

Astationary fitting; 6.15 is secured against. the plate. 3,6.. and extends.. through. the` cover 56. with a steam tight. connectionrtherewith andreceives a steam supply pipe 68 in any suitable manner., such as by. screwethreadsFig. 1. As indicated, the outer end of the-fitting. 61 carriesa jam nut 65 screw-threadedlyengaging. with it. externally. of the housing cover 56 so that the nut SQ may be drawnagainst a. faced. area of. the cover4 56 to form the seal. The. tting..6|.has an internal boreinterconnectingE thel dischargen end of. the pipe withanlopeningin-:the endv ofthe valve. 50 so that. the steam supply is available atall times within the chamberjformedin, the valve itself. That portion ofv the bodyy l0. through which the valve 6. ,extends.carries.counterbores 1U., and 1i substantially. 180 degreestherearound opposite the. respectiveA openngsEA and 65" and the valve 60 is fitted externally with one or more. rings 12,- herein shown astwo yin number, in slots therearoundso. that these rings mayspring into. corresponding slots substantially half their. thickness provided in.the-body. lbetween these two.counterbores.10..and-Fig. 1, so asto pre.- vent steam from traveling longitudinally of. the valve, along its external facety Preferably. like rings 13- and 14.- encirclethe. valve 6.0.- to engage` in receiving. slots inthe body..` lll. outside of these bores10. and. 1I. so. as,.to prevent steam from escaping. therefrom.A toward, the bearings 6 I t and 62. Bronze` rings. 'I5 .and .1.6.. are xedfin position. outside. of the bearings 6lfand62 to engage withy a running. tabout the.. valve60 sotassto prevent any appreciable. f amount of steam;- from leaking from. the. ends of thevalvesexternally. thereof to these. samebearings. It..is..to..be notedthat allof these rings-12i 13.-.and.`hlv spring into the slots. provided in, the. body. land remain stationary irrespect. to. .turningvof the valve. 6D, therelrly.A4 forming ineect a .labyrinth sealaround which steam may.' followonly atortuous. path.4 The. vvalve 6l). is. turnedatfthe. same speed .as that of the. shaft` 41, the. ratio. betweenY the gears .58 and 51 beingV one to one.

. The gear 59. is rlxed on the outer end of an i exhaustvalve 1 1. whichr isjsulo'stantially a coun.-

terpart of thevalve, being-a.hollowcylindrical member having ports 18^`and"l9"` to register respectively upon turning with openings 80 and 8| between the cylinders II, I3 and I2, I4. The valve 'II is mounted on the ball bearings 82 and 33 and has a discharge end opening axially into a tting 84 which is a duplicate of the tting 6l and has its outer end interconnected with the housing 56 with a steam tight joint formed by the jam nut 35. The steam exhaust pipe 86 is fixed in position by screw-threadedly entering the tting 84. The exhaust valve 'I1 has its chamber in the body I9 relieved by the counterbores 81 and 83 extending substantially 180 degrees around the chamber opposite the respective cylinder openings 80 and 8|. Travel of steam longitudinally of the valve Il between the counterbores and the ball bearings carrying the valve is prevented by means of the encircling rings 89 and 90, 9|, these rings `becoming fixed in position within grooves provided in the body member lil. In reference to these rings about the exhaust valve and also about the intake valve, it is to be pointed out that these rings are not tted tightly but with a free running t in respect to the valves themselves. The purpose of these rings is not to make a metal to metal contact but to provide a tortuous passageway thereacross to retard and reduce the flow of steam to substantially nothing.

Referring again to the rotors I8, 24 secured together as a unit, openings are provided through the bosses 23 and 25 to permit a free passageway between the interior cavities within thelrotors. Bearing washers 92 and 93 surround the trunnions 22 and 29 respectively and are carried in counterbores on the side faces of the rotors I8 and .24 to bear with a running t against the plates 42 and t. Each of these washers 92 and 93 is provided with a plurality of holes 94 drilled therethrough and the rotors behind these washers are provided with openings registering with these holes so that there is a communication from the outer side of the washers directly with the cavities within the rotors. In like manner washers 95 and 96 are providedon the trunnions 34 yand 35. preferably made out of some suitable bearing material, such as bronze, to bear against steel or cast iron as the case may be, and serve as thrust washers. Their diameters are limited as indicated in the drawings, Fig. 2, so that when any one or more washers are under a thrust load, their actual bearing area against the cover plate is relatively small and confined closely to the axis of rotation whereby frictional drag is reduced to a minimum.

Where the engine is to be built in a relatively small unit, as above indicated, the sides of all four rotors are provided with a plurality of concentric ribs 91 which may take any form, either square, round, or as indicated in the present showing, triangular shape in section. The partition I an-d the plates 35 and 42 are each provided with a series of complementary ribs so that a tortuous passage is set up for any steam tending to escape from the annular chambers about the rotors along the sides of the rotors toward the axes thereof, the interfltting ribs serving as labyrinth packing as indicated in the copending application of Charles M. Lumey for U. S. Letters Patent, Serial No. 180,522, filed December 18, 1937, now matured as Patent No. 2,211,447. However, in larger units, these ribs 91 are dispensed with and any steam flowing between the sides of the rotors and the cover plates reaches the thrust washers and may dis- These washers in al1 instances are charge into the cavities provided within the rotors. i In fact any steam getting past the ribs 91 in the smaller units will also arrive in these cavities, and in both instances a pressure is built IOL up within the rotors eventually approaching, if not equalling, the steam pressure initially supplied in theiannular chambers about the peripheries of the rotors. In other words it is of no serious consequence if there be a slight leakage past the sides of the rotors since the internal pressure built up within the rotors will eventually equal the pressure of the steam tending to travel theretoward and thereby prevent and stop further leakage, the one pressure opposing the other.V rlhe same idea prevails in case steam leaks on beyond the trunnions of the respective rotors and escapes through the respective bearings into the chambers outside of the plates 35 and 42 bounded by the covers 43 and 56. Pressure is preferably built up in these chambers from such leakage so as to effectively stop any additional leakage. The unit 54 effectively prevents escape of steam from the chamber between the plate 42 and cover 43 along the shaft 41.

rSince there are no moving parts through the cover 56, and the intake and outlet steam pipes are sealed against leakage and their passage through the cover, there are no moving parts about which steam may escape from that chamber.

It is necessary, of course, to provide ample lubrication for an engine of this type where all of its moving parts are sealed within a compact housing. Since the various parts are operating in the presence of a pressure induced by the steam employed for operating the rotors, a pump unit 98 commercially obtainable and having a multiple` number of outlets is employed. This unit 'is mounted through the cover 53 with a steam tight connection therewith and is gear driven from a shaft 99 having a pinion I lli) carried within the trunnion 29 to engage teeth cut internally thereof. From the pump 98 lead a plurality of oil lines mi to the various bearings.

. This oil is supplied under pressure so that it will flow into the various bearings and cavities to which the oil lines lead. The pump 98 may, of course, be of any suitable construction but is preferably of a rotary type. Drainage from the cylinders I3 and I4 is provided through a removable plug Iil2, Fig. 2, which screw-threadedly engages in a conical bore in the under side of the body I9 and has passageways m3 and |94 leading from the respective cylinders thereto.

Steam collecting within the cavities within the rotors may condense to some extent when the engine becomes stationary but any moisture left therein will be converted into steam again upon further operation of the engine, It is to be noted further, Figs. 3 and 4, that the rotors are counterbalanced inrespect to the vanes extending therefrom by means of the masses |634 and |05 of weight extending inwardly from the rotor peripheries on sides opposite the vanes.

In describing the operation `of the engine,

I reference is first made to Fig. 3 wherein the rotors IS and are shown in those positions wherein the vanes 22 and 32 have traveled in the directions of the arrows from their contacting positions to bring the upper vane 2i) past the opening 64 and the lower vane 32 thereunder. The small teeth i9 are in mesh and a closed initial clearance chamber is then deiined betweenthe vanes 2li and 32 and the intermeshing teeth I9.

Rotation of the rotors is had through expansion ofv thesteam against the vanes 28and33 ofthe other rotors to-continue travel of the rotors I8 and Sllinthe directions indicated' and. to rotateV the valves 6&3 and l-IA so as to uncoverY theport 63 by the opening 641 andv permit admissionv of steam into this initial clearance volume ofY the two oylindersinwhich the rotors operate. Simultaneously theY port 'lilA of the exhaust valve 1:1, turning counterclockwisa Fig. 3, begins to register with the exhaust opening 8B, steam is admitted between thevanes Ell and 32'A until the port 63- travels around beyond the intake-opening 64= to close off thesteam admission. Means may be. introduced to. vary the period of admission, suchV means being in addition to the valve: structure shown-and described and constituting av separate, invention and, therefore, not herein shownv and` described- As the vanes 2lil and 32 revolve. around, one: away from the other from the opening B4, theyr travel in their respective cylinders to approach the exhaust opening 8d and, therefore, sweep; ont remaining steam from a previous operation through the opening Sil, t-he Valve port 'IB andi theavalvel l1' itself for discharge through the exhaust pipe BE. Following the closure'of bothinetake, and exhaust valves 60 and l1', the vanes 2 and 32 sweep on around one in immediate.

contact with the other through the positions as.

indicated in Fig. 5 and on to the positions shown.

in Fig. 3, immediately followingv which steamis againadmitted for the next steam admittance..

rllhe rotors 201' and 3i, having their vanes 2B\ and removed 180 degrees respectively fromv their interconnected rotors lil and: 39- receive. steam thereagainst 180 degrees following` ad`- mittanoe between the rotors t8 and- 310this admittance being controlled by the valveV ports. liliv and i9 located- 1.80A degrees around; their respective va-lves E@ and ifi from the ports 63e andl; Without in any way limiting the inventionfhereby but morder topermit visualization-of the proportions of. theengine in one particular size-for a conservative two horse power rating at 800. revolutions. per minute, each cylinder is six inches ini diameter and each rotor is formed on a. ve inch pitch diameter with a; width of 1.750 inches` tohave seventy-six minor teethv I9; twenty pitch epicycloidA tooth form, The Vanesare given one; half. pitch, stubtooth form; In. the-position of: the rrotors shown in Fig. 3, wherethe-intake valve 69 is just on the point of openingthe center lineY of the vane 32 through the axis offthe rotorisy forty-six degrees abovethe horizontal center; line: through the cylinder i3 while the center. line oi thevane 2i) through its axis is ten degreesbelow the-horizontal center line of the cylinder H.;

The clearance volume at zero degrees intake portopening is 4.09 cubic inches. The openings of the ports in theintake valve are proportionedvv to have-steam cut-off.' after 170 degrees-of. open.- ing, the intake valve ports inthe body I 0 measure seventy degrees included angleffrom'the. valveaxis while theports in theV intake: valveiitselfmeasure one hundred degrees: included: angle; from the. center of the valve axis. The rotorsr travelf be'- tweenV inlet and cut-oilA of the intake valve. 1'60 degreesv with a ten degree ,valve leadgiving the totalirotor rotation of 170' degrees before. cnt-off. It is to be noted that the exhaust. valve. 'H1 closessits ports for thev respective pairsorotors' prior to the passage ci the'vanes therepast. This. ineens;` as-best. illustrated in- Fig'. 4, that: follow.- ing the out-orf` by the exhaustva1ve,;there is; a.

volume. of; steam or gases` left to be compressed between. the rotors as they continue on around tolbring the=vanesto those positions indicated in Fig. 5; rlfhis` means that in the residual gas volume left within thefcylinders following closure of. the exhaust valvea pressure is built up which tends todissipate in part transversely between theupper andlower rotors between the teeth I9. However, steamipressureexists on the other side toasgreatora greater degree so that the steam onthepower; side does not leak back in opposition tothat pressure and that residual pressure may be dissipatedby.- leakage in part down past the sides of' the rotors and into the rotors to maintain theopposition pressure above indicated.

Whilethe invention hasbeen herein shown and described in the one-particular form, it is obvious thatstr-uctural..variations may be employed with-` ders formed: inthebodyV coaxialiy aligned with.

the respective cylinders in; the rst pair, apartition in the body between said pairs havingr openings; therethrough coaxial with the respective cylinder-s. ineach. of: said pairs, a rotor in each ofl said,v cylinders, said rotors being connected and secured one to` the. other in pairs through said partition: openings,J said rotors having chambersv therein andhaving; communication one with another through.- said-rotor connections, each ofr said rotors havinga major toothed peripheral portion of less diameter than that of its cylinder, a vane extendingefromeach rotor. into close, free running ta with the peripheral wall of its cylinder, each rotor havingV a depressed peripheral portion adjacentfits-vane', the axes of said cylinders being loeatedto have the-rotor in one cylinder in tooth meshing engagement With-the rotor in the intersecting cylinder, said rotors being meshed to have the vane of one; rotor follow in meshing engagement behind'the-Vanefof the other rotor to main'- tain ai. continuous tooth seal between the rotors, means'for admitting fluid into the cylinders in timed sequence with travel of said vanes for. movementthereof', said 11o-tors` being formed to have-a close; freerunning side nt with the ends of theirrespective cylinders, and fluid passage.- ways removed a distance from the rotor peripheries and carried through the rotor sides into said rotor chambers,v whereby'fluid escaping between the rotors. and the cylinder ends may collect and build uppressure within the rotors to oppose furthe-r fluid flow thereto inthe absence of packing.

2. Ina. rotary engine, a body, a pair of periphorally` intersecting cylinders formed in the body, a second7 pair of peripherally intersecting cylinders. formed in. the body' coaxially aligned withV the respective-cylinders in the rst pair, a parti.- tion: inthe body. betweensaid pairs having Openings therethrough ooaxialwth the respective cyla: Vanerextending. from' each. rotor intoclose, free running fit with the peripheral wall of its cylinder, each rotor having a depressed peripheral portion adjacent its vane, the axes of said cylinders being located to have the rotor in one cylinder in tooth meshing engagement with the rotor in the intersecting cylinder, said rotors being meshed to have the vane of one rotor follow in meshing engagement behind the vane of the other rotor to maintain a continuous tooth seal between the rotors, means for admitting fluid into the cylinders in timed sequence with travel of said vanes for movement thereof, said rotors being formed to have a close, free running side fit with the ends of their respective cylinders, and fluid passageways removed a distance from the rotor peripheries and carried through the rotor sides into said rotor chambers, whereby fluid escaping between the rotors and the cylinder ends may collect and build up pressure Within the rotors to oppose further fluid how thereto in the absence of packing, a fluid exhaust valve, and timing means closing ofi said valve before the vanes of intermeshed rotors come together to permit further travel of those vanes to build up a pressure Within their cylinders against the intermeshing teeth ahead of the vanes.

3. In a rotary engine, a body, a pair of peripherally intersecting cylinders formed in the body, a second pair of peripherally intersecting cylinders formed in the body coaxially aligned with the respective cylinders in the first pair, a partition in the body between said pairs having openings therethrough coaxial with the respective cylinders in each of said pairs, a rotor in each of said cylinders, said rotors being connected and secured one to the other in pairs through said partition openings, said rotors having chambers therein and having communication one with another through said rotor connections, each of said rotors having a major toothed peripheral portion of less diameter than that of its cylinder, a vane extending from each rotor into close, free running t with the peripheral wall of its cylinder, each rotor having a depressed peripheral portion adjacent its vane, the axes of said cylinders being located to have the rotor in one cylinder in tooth meshing engagement with the rotor in the intersecting cylinder, said rotors being meshed to have the vane of one rotor follow in meshing engagement behind the vane of the other rotor to maintain a continuous tooth seal between the rotors, means for admitting fluid into the cylinders in timed sequence with travel of said vanes for movement thereof, said rotors being formed to have a close, free running side t With the ends of their respective cylinders, and uid passageways removed a distance from the rotor peripheries and carried through the rotor sides into said rotor chambers, whereby fluid escaping between the rotors and the cylinder ends may collect and build up pressure within the rotors to oppose further fluid flow thereto in the absence of packing, side plates on said body forming end closures for said cylinders, bearings in said plates carrying each pair of connected rotors, `and a pressure chamber outside of at least one plate initially receiving fluid leakage through said bearings to build up a residual pressure opposing further leakage.

4. In a rotary engine, a pair of circumferentially intersecting cylinders, a second pair of circumferentially intersecting cylinders, said cylinders being arranged to have a cylinder of each pair to one side of their intersections ooaxially aligned and the other cylinders also being like- Wise coaxially aligned, a toothed driving rotor in each cylinder in mesh with the rotor in the intersecting cylinder, means securing in driving relation one rotor to the other between coaxial cylinders, a drive shaft having driving engagement with one rotor and extending axially through and beyond its connected rotor, a bearing supporting the shaft beyond said connected rotor, and bearings supporting each pair of the connected rotors independently of said shaft.

EARL E. BOWERS.

CHARLES M. TUMEY. 

